maven利用各种插件来管理构建项目，本文记录下工作中常用到的插件及使用方法。每个插件都会提供多个目标(goal)，用于标示任务。各插件配置在pom.xml里，如下：

<build>

  [...]

  <plugins>

    <plugin>

      ...

    </plugin>

  </plugins>

  [...]

</build>

常用插件见：http://maven.apache.org/plugins/index.html，http://www.mojohaus.org/plugins.html。

maven-compiler-plugin

用于编译源代码，默认在compile阶段被调用。两个goal，compiler:compile/compiler:testCompile

<plugin>

    <groupId>org.apache.maven.plugins</groupId>

    <artifactId>maven-compiler-plugin</artifactId>

    <version>3.3</version>

    <configuration>

        <!--源码的Java版本-->

        <source>1.7</source>

        <!--运行环境的Java版本-->

        <target>1.7</target>

    </configuration>

</plugin>

maven-surefire-plugin

test阶段执行单元测试，路径src/test/java

<plugin>

  <groupId>org.apache.maven.plugins</groupId>

  <artifactId>maven-surefire-plugin</artifactId>

  <version>2.18.1</version>

  <configuration>

    <!--不执行的单元测试文件-->

    <excludes>

      <exclude>bvt/*.java</exclude>

    </excludes>

    <!--并行运行-->

    <parallel>methods</parallel>

    <threadCount>10</threadCount>

  </configuration>

</plugin>

appassembler-maven-plugin

生成启动Java应用的脚本，命令 mvn package appassembler:assemble

<plugin>

<groupId>org.codehaus.mojo</groupId>

<artifactId>appassembler-maven-plugin</artifactId>

<version>1.10</version>

<configuration>

  <!-- Set the target configuration directory to be used in the bin scripts，默认路径是etc -->

  <configurationDirectory>configuration</configurationDirectory>

  <!-- 源配置文件目录，默认目录是src/main/config -->

  <configurationSourceDirectory>src/main/resources</configurationSourceDirectory>

  <!--Copy the contents from configurationSourceDirectory to the target configuration directory-->

  <copyConfigurationDirectory>true</copyConfigurationDirectory>

  <!-- Include the target configurationDirectory in the beginning of the classpath declaration in the bin scripts -->

  <includeConfigurationDirectoryInClasspath>true</includeConfigurationDirectoryInClasspath>

  <!--assemble the artifacts in and place the bin scripts-->

  <assembleDirectory>release</assembleDirectory>

  <!--jar存放目录-->

  <repositoryName>lib</repositoryName>

  <!--lib下直接存放jar，没有路径文件夹（如com/apache)-->

  <repositoryLayout>flat</repositoryLayout>

  <programs>

    <program>

      <!--指定主类，脚本名。会生成shell/bat两种类型,也可用platforms指定运行平台-->

      <mainClass>com.mycompany.app.App</mainClass>

      <name>startapp</name>

    </program>

  </programs>

</configuration>

</plugin>

maven-assembly-plugin

对项目的源码、jar包、依赖、文档、目录等文件归档生成分发包，支持jar/war/zip/tar/tar.gz等归档格式。如写mapreduce job时可以使用生成一个jar包，包含所有的依赖，便于上传job。
命令mvn assembly:single，也可以绑定到package阶段，自动执行。下面的配置会生成如下文件：target/sample-1.0-SNAPSHOT-jar-with-dependencies.jar

<plugin>

  <groupId>org.apache.maven.plugins</groupId>

  <artifactId>maven-assembly-plugin</artifactId>

  <version>2.4</version>

  <configuration>

    <descriptorRefs>

      <!--使用插件提供的配置，包含jar和依赖-->

      <descriptorRef>jar-with-dependencies</descriptorRef>

    </descriptorRefs>

    <!--也可以自定义打包内容，使用descriptor指定路径-->

    <!--descriptor>src/main/assembly/assembly.xml</descriptor-->

  </configuration>

  <executions>

    <execution>

      <id>make-assembly</id>

      <!--目标single绑定到package阶段，package阶段自动被调用-->

      <phase>package</phase>

      <goals>

        <goal>single</goal>

      </goals>

    </execution>

  </executions>

</plugin>